Flanging device for pre-flanging and flanging of components

ABSTRACT

A hemming or flanging device is provided for the prehemming and finishing hemming of components with a first component having an upright standing flange before hemming and a second component with a flat edge area. The device includes a folding bed performing the hemming stroke with support surfaces for the components arranged to be approached at least in an edge area. At least one prefolding jaws movable into a prehemming position, with a flange contact surface arranged obliquely to the flange. At least one finishing folding jaw has contact surfaces arranged in parallel to the edge area. A finishing folding jaw slide moves the finishing folding jaw from an outside to an inside into a finishing hemming position. A prefolding jaw slide or a pivoting plate moves the prefolding jaw from the outside to the inside into the prehemming position and relative to the finishing folding jaw slide.

The present invention pertains to a hemming device according to thepreamble of patent claims 1 and 2.

“Hemming” is defined as the positive-locking connection of two parts byfolding over a flange. Especially an outer sheet metal and an innersheet metal are connected to one another hereby in the manufacture ofvehicle bodies.

For example, the following systems are available for the hemming of bodyparts:

1. Hemming tools which are used in presses and perform the prehemming orfinishing hemming of the flange by a vertical movement of the upper partof the tool. Such a hemming process has been known from DE 44 18 684 A1,where a slide moves radially inwardly and subsequently again radiallyoutwardly for the prehemming and a second hemming tool is displacedvertically by means of the press punch for the finishing hemming.Special efforts are needed for feeding and removing the components dueto the arrangement of the press above the folding bed. Above all, theupper tool must perform a long stroke.

2. Hemming devices in which the hemming bed is stationary and the flangeto be hemmed is bent over by hydraulically or electrically operatedslides or mechanical rocker arm elements. The actuation and operation ofthe hemming slides and the rocker arm element are complicated (cf. DE197 47 292 C1).

3. A hemming device of this class has been known from U.S. Pat. No.5,150,508, in which the lower folding bed, on which the sheet metals tobe connected are placed, performs a separate hemming stroke for theprehemming and the finishing hemming and presses in the process theflange to be folded one after another against the stationary prefoldingjaws and finishing folding jaws. The prefolding and finishing foldingjaws are arranged rigidly on a horizontally displaceable slide. Thefolding bed must be displaced vertically and the folding jawshorizontally for the prefolding and the finishing folding. The foldingbed must then perform a long displacement travel between the prefoldingoperation and the finishing folding operation and the hemming strokeproper in the particular positions.

The basic object of the present invention is to propose a device of thisclass, in which the vertical movement of the folding bed is limited to aminimum and the prefolding and finishing folding jaws are brought intoposition by secure and simple movements.

To accomplish this object, it is proposed that the prefolding jaw isalso displaceable from the outside to the inside into the prehemmingposition by means of a slide and relative to the slide of the finishingfolding jaw.

As an alternative to the displaceability of the prefolding jaw, it isproposed according to the present invention that the prefolding jaw isfastened to a pivoting plate and can be pivoted from the outside to theinside into the prehemming position by actuating the pivoting plate, andthat the pivoting plate can be locked with the prefolding jaw fastenedto it in the prehemming position. Meaningful embodiments for this areshown in the subclaims 3 through 10.

Due to the fact that the folding jaws can be displaced according to thepresent invention on slides of their own possibly independently from oneanother into the hemming position above the folding bed for theprefolding and the finishing folding, the displacement travel of thefolding bed can be considerably reduced. The prefolding and finishingfolding jaws can be brought one after another into the same hemmingposition especially if the guide paths of the two slides are arranged atacute angles in relation to one another, so that a long adjustmentmovement of the folding bed between the prefolding and the finishingfolding is not necessary. Consequently, the folding bed performs onlythe hemming stroke proper each time for the prefolding and the finishingfolding, and this hemming stroke takes place at one and the same point.The same is also possible in the alternative embodiment, the combinationof the pivotable prefolding jaw with the displaceable to finishingfolding jaw.

It proved to be favorable to arrange the slide for prefolding or thepivoting plate on the slide for finishing folding or vice versa. In thisso-called piggyback arrangement or slide-on-slide arrangement, thedisplacement travels for the individual slides are limited to a minimum.In addition, an especially compact design is possible. A spring actuatedholding-down device, which fixes the two sheet metals on the surface ofthe folding bed already before the beginning of the prefolding andfinishing holding operation, may be arranged on the upper slide,preferably the slide for the prefolding or on the pivoting plate.

It proved to be favorable in the alternative embodiment according to thepresent invention to mount the drives for the slide with the finishingfolding jaw and the pivoting plate on a common bracket in an articulatedmanner, wherein the bracket itself is rigidly connected to the base.Moreover, the pivoting plate may be mounted on another bracket, which islikewise rigidly connected to the base or to the slide, in a rotatinglymovable manner via an additional hinge.

The pivoting plate can be locked in the working position by a lockingunit, which is brought into the locked position by a movement of theslide for the finishing folding with the existing drive unit beingarranged on the slide for the finishing folding. However, the pivotingplate and the slide may also be coupled with one another such that theprefolding and finishing folding jaws can be forcibly moved one afteranother into the working position with a common drive unit. It proved tobe favorable in this connection to arrange stops at the pivoting plateand the slide, which are brought into contact for locking the prefoldingjaws. The pivoting plate can then be pivoted upwards by means of aconnecting link guide present at the slide for the subsequent finishingfolding. Only one drive unit is necessary here for the linear movementof the slide, because the pivoting plate is inevitably also actuated atthe same time with the movement of the slide.

The present invention will be explained in greater detail on the basisof FIGS. 1 through 7 attached. In the drawings,

FIG. 1 shows a side view of a detail of the slide-on-slide arrangement,

FIG. 2 shows a sectional view for FIG. 1 in the so-called zero position,

FIG. 3 shows a corresponding sectional view in the prefolding position,

FIG. 4 shows a sectional view in the finishing folding position,

FIG. 5 shows a side view of a detail of the combination of the pivotingplate and the slide in the prefolding position,

FIG. 6 shows the pivoted-back position of the pivoting plate for FIG. 5,and

FIG. 7 shows an embodiment for the actuation of the pivoting plate andthe slide with a drive unit.

The figures show the outer edge of a folding bed 4 with the outer edgesof the body sheets 5 and 6, which outer edges lie on the said outeredge. For hemming, e.g., an automobile door, a folding bed 4 is arrangedunder the entire door. The folding bed 4 with the sheets 5, 6 lying onit is raised with the hemming stroke and pressed one after anotheragainst the oblique contact surface 14 of the prefolding jaw 9 andagainst the horizontal contact surface 15 of the finishing folding jaw10 for the two-step folding over of the upright flange 7 with theexception of the flat edge area 8. As is apparent from FIG. 1, the lowerslide 2 is displaceable for the finishing folding on a base 1 onhorizontal guide paths 19. The drive 12 for the slide 2 is supported onthe frame 1 via the fastening 11. On the side facing the folding bed 4,the finishing folding jaw 10 is detachably fastened to the lower slide2, e.g., by a screw connection. The upper slide 3 is displaceable on theslide 2 for prefolding on the guide paths 20 in the direction of thedouble arrow shown. The guide paths 20 are arranged at an acute angle,preferably at an angle of 25° in relation to the guide paths 19. Thedrive 13 for the slide 3 is supported on the slide 2 via the fastening16. The prefolding jaw 9 is preferably fastened detachably to the slide3.

In the zero position shown in FIG. 2, the upper slide 3 with theprefolding jaw 9 and the lower slide 2 with the finishing folding jaw 10are in the retracted position The folding bed 4 with the components 5and 6 is lowered into the lower end position. The holding-down device 17fastened to the upper slide 3 is held in the extended lower position bythe spring 18 or in some other way.

In the prefolding position according to FIG. 3, the slide 2 with thefinishing jaw 10 is in the zero position. The slide 3 with theprefolding jaw 9 moves by about 50-60 mm at an angle of 25° in relationto the horizontal direction and can be locked by means of toggle levers,not shown, or in some other way. The holding-down device 17 is in theextended position under the force of a spring. The folding bed 4 movesupward into the hemming stroke, while the sheet 6 is fixed in itsposition by the holding-down device 17 by the force of a spring. Theflange 7 is brought into an approximately 45° position during thehemming stroke by the oblique contact surface 14 of the prefolding jaw9. After the conclusion of the prefolding operation, the folding bed 4moves downward by the hemming stroke and the slide 3 returns into thezero position.

In the finishing folding position according to FIG. 4, the slide 3 withthe prefolding jaw 9 is in the zero position. The slide 2 with thefinishing folding jaw 10 moves to the stop. The holding-down device 17is in the extended position under spring force. The folding bed 4 movesupward by the hemming stroke, while the sheet 6 is fixed in its positionby the holding-down device 17 by spring force. After the conclusion ofthe folding operation, the folding bed 4 moves downward by the hemmingstroke and the slides 2 and 3 return into the zero position.

The hemming device according to the present invention makes possible asubstantial reduction of the vertical movements of the folding bed 4.This happens due to the fact that the prefolding and finishing jaws arebrought one after another into the same folding position by means of ahydraulic, pneumatic or electric drive.

In the views in FIGS. 5 and 6, the prefolding jaw 21 is rigidlyconnected to the pivoting plate 24. The pivoting plate 24 is mounted onthe bracket 28 in a rotatingly movable manner by means of the hinge 26,on the one hand, and, on the other hand, it is pivoted by means of thedrive 22. The drive 22 is connected via the hinge 25 to the pivotingplate 24 and via another hinge to the bracket 23 which is fastened tothe base 1. In the prefolding position according to FIG. 5, the pivotingplate 24 is secured by means of the locking mechanism 29. The lockingmechanism 29 arranged rigidly on the slide 2 is moved to and frotogether with the slide 2 by actuating the drive 12. According to FIG.6, the bracket 28 is rigidly connected to the base 1. To make possible arelative movement between the slide 2 and the bracket 28, the slide 2 isprovided with an elongated hole in the area of the hinge 26.

In the embodiment according to FIG. 7, only one drive unit 30, whichmoves the slide 2 linearly to and fro, is provided, contrary to theembodiment according to FIGS. 5 and 6, instead of the two drive units 12and 22. To lock the prefolding jaw 21 in the prefolding position beingshown, a lower stop 32 is fastened to the slide 2 and an upper stop 33is fastened to the pivoting plate 24. When the slide 2 is moved to theleft in the view by means of the drive unit 30 after the conclusion ofthe prefolding, the connecting link guide 31 arranged rigidly on theslide 2 is also moved at the same time, and the pivoting plate 24fastened to the bracket 28 is moved with the roller 34 in the connectinglink guide 31 such that the prefolding jaw 21 is pivoted upward in theprocess.

The process is essentially as follows in the “slide-on-slide” system:

1. Transfer of the components 5, 6 to the folding bed 4

2. The upper slide 3 with the prefolding jaw 9 moves forward into thefolding position

3. The folding bed 4 with the components 5, 6 lying on it moves upwardagainst the prefolding jaws 9 (prefolding)

4. The folding bed 4 with the prefolded flange 7 moves into thelowermost position

5. The upper slide 3 moves back

6. The lower slide 2 with the finishing folding jaw 10 moves forwardinto the folding position

7. The folding bed 4 with the components 5, 6 lying on it moves upwardagainst the finishing folding jaws 10 (finishing folding)

8. The folding bed 4 with the finished folded component moves into thelowermost position

9. The lower slide 2 moves back

10. The finished folded component is removed.

The process is essentially as follows in the “pivoting plate and slide”system:

1. Transfer of the components 5, 6 to the folding bed 4

2. Pivoting of the prefolding jaws 21 into the prefolding position

3. Forward movement of the slide 2 to lock 29 the prefolding jaws 21(see FIG. 5)

4. The folding bed 4 with the components 5, 6 lying on it moves upwardagainst the prefolding jaws 21 (prefolding)

5. The folding bed 4 with the prefolded flange 7 moves into thelowermost position

6. The slide 2 moves back to unlock the prefolding jaws 21

7. Pivoting back of the pivoting plate 24 into the position according toFIG. 6

8. The slide 2 with the finishing folding jaws 10 moves forward into thefinishing folding position

9. The folding bed 4 with the component lying on it moves upward againstthe finishing folding jaws 10 (finishing folding)

10. The folding bed 4 with the folded component moves into the lowermostposition

11. The slide 2 moves back

12. The finished folded component is removed.

The process is as follows for the system according to FIG. 7:

1. The slide 2 is in the intermediate position, the pivoting plate 24 ispivoted up

2. The components are transferred to the folding bed 4

3. The slide 2 with the connecting link guide 31 moves back, theprefolding jaw 21 is pivoted in downward, automatic locking by the stops32 and 33 (see FIG. 7)

4. The folding bed 4 with the components 5, 6 lying on it moves upwardagainst the prefolding jaws 21 for prefolding

5. The folding bed 4 with the prefolded components moves into thelowermost position

6. The slide 2 moves forward until the prefolding jaw 10 is in thefinishing folding position; pivoting up of the prefolding jaw 21 at thesame time

7. The folding bed 4 with the prefolded component lying on it movesupward against the finishing folding jaws 10 for the finishing folding

8. The folding bed 4 with the finished folded component moves into thelowermost position

9. The slide 2 moves back into the intermediate position

10. The finished folded component is removed.

LIST OF REFERENCE NUMBERS

1 Base

2 Lower slide (for finishing folding)

3 Upper slide (for prefolding)

4 Folding bed

5 Lower component, body sheet

6 Upper component, body sheet

7 Upright flange of 5

8 Flat edge area of 6 (horizontal)

9 Prefolding jaw

10 Finishing folding jaw

11 Fastening for 12 to 1

12 Drive for 2

13 Drive for 3

14 Contact surface on 9 (oblique)

15 Contact surface on 10 (horizontal)

16 Fastening for 13 to 2

17 Holding down device

18 Spring

19 Horizontal guide path of 2

20 Oblique guide path of 3

21 Prefolding jaw

22 Drive for 21

23 Bracket for 12 and 22 on 1

24 Pivoting plate

25 Hinge between 22 and 24

26 Hinge between 24 and 28

27 Elongated hole in 2 for 26

28 Bracket on 1

29 Locking mechanism on 2 for 21

30 Common drive unit for 2 and 14

31 Connecting link guide (rigidly attached to 2)

32 Stop, lower (rigidly attached to 2)

33 Stop, upper (rigidly attached to 24)

34 Roller on 24

What is claimed is:
 1. A hemming device for the prehemming and finishinghemming of components with a first component having an upright standingflange before hemming and second component with a flat edge area, thedevice comprising: a base; a folding bed performing the hemming strokewith respect to said base, said folding bed having support surfaces forthe components arranged to be approached at least in an edge area; atleast one prefolding jaw movable into a prehemming position, with aflange contact surface arranged obliquely to said flange; at least onefinishing folding jaw having contact surfaces arranged in parallel tosaid edge area; a finishing folding jaw slide moving said finishingfolding jaw from an outside to an inside into a finishing hemmingposition; and a prefolding jaw slide displacing said prefolding jaw fromthe outside to the inside into the prehemming position and relative tosaid finishing folding jaw slide.
 2. A hemming device in accordance withclaim 1, wherein each slide is displaceable along respective guide pathsextending at an acute angle in relation to one another.
 3. A hemmingdevice in accordance with claim 1, wherein said prefolding and finishingfolding jaws have contact surfaces movable one after another into thehemming positions by means of the respective slides with said foldingbed performing the same or essentially the same hemming stroke for theprehemming and the finishing hemming.
 4. A hemming device in accordancewith claim 1, wherein one of said finishing folding jaw slide and saidprefolding jaw slide is arranged on the other of said finishing foldingjaw slide and said prefolding jaw slide.
 5. A hemming device inaccordance with claim 1, further comprising a spring-actuatedholding-down device, said prefolding jaw slide being arranged as anupper slide with said holding-down device arranged on said upper slide.6. A hemming device for the prehemming and finishing hemming ofcomponents with a first component having an upright standing flangebefore hemming and a second component with a flat edge area, the devicecomprising: a base; a folding bed performing the hemming stroke withrespect to said base, said folding bed having support surfaces for thecomponents arranged to be approached at least in an edge area; at leastone prefolding jaw movable into a prehemming position, with a flangecontact surface arranged obliquely to said flange; at least onefinishing folding jaw having contact surfaces arranged in parallel tosaid edge area; a finishing folding jaw slide moving said finishingfolding jaw from an outside to an inside into a finishing hemmingposition; a pivoting plate, said prefolding jaw being fastened to saidpivoting plate for pivoting from the outside to the inside into theprehemming position and lockable in the prehemming position.
 7. Ahemming device in accordance with claim 6, further comprising afinishing folding jaw slide drive and a bracket, said pivoting plate andsaid finishing folding jaw slide drive being mounted on said bracket inan articulated manner.
 8. A hemming device in accordance with claim 6,further comprising a bracket, a hinge and a base, said pivoting platebeing mounted in a rotatingly movable manner on said bracket, saidbracket being rigidly connected to said base by said hinge.
 9. A hemmingdevice in accordance with claim 8, further comprising a common driveunit, wherein said pivoting plate and said finishing folding jaw slideare coupled with one another such that said prefolding and finishingfolding jaws can be moved one after another into the prehemming andfinishing hemming position via said common drive unit.
 10. A hemmingdevice in accordance with claim 8, wherein a pivoting plate stop and afinishing folding jaw slide stop touch each other for locking saidprefolding jaws with said pivoting plate being pivoted up with saidprefolding jaw around said hinge by displacing said finishing foldingjaw slide into the finishing folding position via a connecting linkguide associated with said finishing folding jaw slide.
 11. A hemmingdevice in accordance with claim 6, wherein said prefolding and finishingfolding jaws have contact surfaces movable one after another intohemming positions respectively by said pivoting plate and said finishingfolding jaw slide with said folding bed performing the same oressentially the same hemming stroke for the prehemming and the finishinghemming.
 12. A hemming device in accordance with claim 6, wherein one ofsaid said pivoting plate and said finishing folding jaw slide isarranged on the other of said pivoting plate and said finishing foldingjaw slide.
 13. A hemming device in accordance with claim 6, furthercomprising a spring-actuated holding-down device arranged on saidpivoting plate.
 14. A hemming device in accordance with claim 6, furthercomprising a bracket and a hinge, said pivoting plate being mounted in arotatingly movable manner on said bracket, said bracket being rigidlyconnected to said finishing folding jaw slide by said hinge.
 15. Ahemming device for hemming a workpiece, the device comprising: a base; afolding bed supportable of the workpiece and movable with respect tosaid base in a hemming path between a hemming position and a retractedposition; a prefolding jaw movable with respect to said base into andout of said hemming path, said folding bed being movable toward saidprefolding jaw arranged in said hemming path to pre-fold a flange of theworkpiece; a finishing jaw movable with respect to said base into andout of said hemming path, said folding bed being movable toward saidfinishing jaw arranged in said hemming path to finish fold the flange ofthe workpiece, said prefolding jaw and said finishing jaw being movablein separate directions angularly spaced from said hemming path.
 16. Adevice in accordance with claim 15, wherein: said prefolding jaw ismovable Into said hemming position to pre-fold the flange of theworkpiece; said finishing jaw is also movable into said hemming positionto finish fold the flange of the workpiece.
 17. A device in accordancewith claim 15, wherein: said prefolding jaw includes a flange contactsurface arranged obliquely to said flange; said finishing jaw has acontact surface arranged substantially parallel to said folding bedsupporting the flange of the workpiece.
 18. A device in accordance withclaim 15, wherein: said prefolding jaw and said finishing jaw have oneof a slide and pivot connection to said base; one of said finishing jawand said prefolding jaw is arranged on the other of said finishing jawand said prefolding jaw.